Effect of Target Change During the Simple Attack in Fencing
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Journal of Sports Sciences, 2013 Vol. 31, No. 10, 1100–1107, http://dx.doi.org/10.1080/02640414.2013.770908 Effect of target change during the simple attack in fencing MARCOS GUTIÉRREZ-DÁVILA1, F. JAVIER ROJAS1, MATTEO CALETTI2, RAQUEL ANTONIO3, & ENRIQUE NAVARRO3 1University of Granada, Faculty of Sport Sciences, Department of Physical Education and Sports, Granada, Spain, 2University of Granada, Faculty of Psychology, Granada, Spain, and 3Technical University of Madrid, Faculty of Physical Activity and Sport Sciences, Madrid, Spain (Accepted 9 January 2013) Abstract The aim of this study was to test the effect that changing targets during a simple long lunge attack in fencing exerts on the temporal parameters of the reaction response, the execution speed, and the precision and the coordination of the movement pattern. Thirty fencers with more than 10 years of experience participated in this study. Two force platforms were used to record the horizontal components of the reaction forces and thereby to determine the beginning of the movement. A three- dimensional (3D) system recorded the spatial positions of the 9 markers situated on the fencer plus the epee, while a moving target was projected on a screen, enabling the control of the target change. The results indicated that when a target change is provoked the reaction time (RT), movement time (MT), and the time used in the acceleration phase of the centre of mass (CM) increases significantly with respect to the attack executed with a straight thrust. The speed and horizontal distance reached by the CM at the end of the acceleration phase (VX(CM) and SX(CM), respectively) significantly decreased, while the errors increased. However, the temporal sequence of the movement pattern did not appreciably change. Keywords: motor control, biomechanics, fencer, reaction response Introduction must wait until the opponent starts the defensive action (Movement Time (MT)-stimulus change). The lunge is one of the most frequently used actions Then, when the defensive action is detected (S ), during the attack in fencing. This technical action is 2 the attacker should inhibit the initial attack, process executed in an uninterrupted way with a temporal the information, and make the most appropriate sequence that begins with the acceleration of the decision while accelerating forwards, this being con- epee arm, then the back foot becomes active fol- sidered “choice reaction time” (CRT). Finally, the lowed by the front foot, and ends when the point of fencer needs sufficient movement time to change the the epee touches the target. During the movement, a aim of the epee and reach the target (MT-target horizontal thrust phase can be distinguished, when Downloaded by [UGR-BTCA Gral Universitaria] at 13:15 14 May 2013 change). Figure 1 shows a sequence of a simple the centre of mass (CM) of the fencer accelerates attack together with the movement phases (upper forwards, leading to a flight phase that ends when the part), as well as a simplified time model of the simple front foot makes contact with the floor (Stewart & attack with only a direct thrust (A) together with a Kopetka, 2005). The movement pattern is based on simple attack involving a target change (B). a model of pushing kinetic chain (Kreighbaum & In the practice of fencing, the simple attack with Barthels, 1996), which facilitates the change in the target change, described in Figure 1 (B), is usually trajectory of the weapon at any instant during the trained for individually, with the coach (master) act- action. ing as opponent and attempting to simulate a real Following classical fencing manuals, the lunge can action (Czajkowski, 2005). Recently, automatic sys- be executed by a straight thrust or by disengage- tems that permit a simulation of this situation ment, changing the target during the action through randomised control of stimuli (Electronic (Thirioux, 1970). Sometimes, the disengagement is Training Target, Favero Electronic Design - Italy) used to change the target during the attack in have been used. Besides the acquisition of a certain response to a defence action. In this case, the fencer functional variability in movement patterns, this type Correspondence: F. Javier Rojas, University of Granada, Faculty of Sport Sciences, Department of Physical Education and Sports, Granada, Spain. Email: [email protected] © 2013 Taylor & Francis Effect of target change in fencing 1101 Figure 1. Schematic representation of the simple attack sequence together with the movement phases (upper part), as well as a simplified temporal model of the simple attack executed with a direct thrust (A) and of the simple attack with a target change (B). (RT = reaction time.) of training is intended to help the fencer reduce their In another sphere, cognitive neuropsychologists choice reaction time, attempting to associate every recognise that the motor planes and their sequencing response with a stimulus. However, studies carried arise in an implicit, unconscious, and automatic way, out that entail varying levels of uncertainty of whereas the intentions of the movements are con- response for the fencer (Borysiuk & Waskiewicz, scious and can be influenced by prior information, 2008; Sanderson, 1983), along with certain explana- giving rise to simple facilitation or priming, which tory theories discussed below, cause us to suspect favours rapid responses (Desmurget & Sirigu, 2009). that the uncertainty produced by target change dur- However, to guarantee adaptability in the responses ing the execution of a movement may reduce the when a target change is required during an action, a velocity of displacement and modify the coordina- facilitation or high-order strategy is necessary to tion of the movement pattern, approximating the enable the inhibition of the first action triggered by context of real competition. a stimulus to refine the precision of the response From the dual-visual-system model, the reaction (Gao, Wong-Lin, Holmes, Simen, & Cohen, 2009). Downloaded by [UGR-BTCA Gral Universitaria] at 13:15 14 May 2013 response requires the contribution of the two visual According to Duque, Lew, Mazzocchio, Oliver, processes that have different functions. A ventral and Ivry (2010), this inhibition process develops by current, associated with explicit awareness, provides two closely related mechanisms. The first inhibits information on the probabilities to execute the action the activation of possible responses selected at the (affordable perception), while a dorsal current gath- spinal level (impulse control to avoid premature ers visual cues implicit in movement control, imme- reactions) and the second determines one response diately and relatively quickly (Goodale & Westwood, among the most relevant options (conflict resolu- 2004; Milner & Goodale, 1995). Following Van der tion). Thus, before the movement starts, all the pos- Kamp, Rivas, Van Doorn, and Savelsbergh (2008), sible responses are activated, requiring inhibitory the ventral current would be more involved before signals at the spinal level, anticipating external infor- starting the movement, while the dorsal would dom- mation that would cause one response to prevail over inate over the ventral during movement execution. all others. This second inhibitory mechanism would Accordingly, in the case of a target change during a occur at the upper cortical levels, causing a certain simple attack, the dominance of the dorsal current delay in the response (Ivanoff, Branning & Marois, would be delayed until the instant at which the target 2009; Schluter, Rushworth, Passingham, & Mills, change occurs, thus slowing down the initial 1998). This aspect could be related to the findings movement. of Di Russo, Taddei, Apnile, and Spinelli (2006), 1102 M. Gutiérrez-Dávila et al. who compared high-level fencers with non-athlete the forte of the epee blade (near the hilt). A projector university students, and showed that the capacity connected to a computer with a programmable that fencers have to change one target to a more external card enabled the timed projection of a circle appropriate one is the result of greater inhibitory of 0.09 m over a white surface of 0.70 × 0.55 m activity by the prefrontal cortex over motor representing a plastron, after a random period of processes. 0.5 s to 1.2 s, from the starting cue. After this period, According to the above-mentioned researchers, an electronic signal was used to synchronise all the the target change in response to the opponent’s recording systems mentioned. defensive action increases uncertainty, delays the Following the protocol used by Williams and dominance of the dorsal current during the attack, Walmsley (2000), for a long lunge the plastron was and activates the inhibitory mechanism of conflict situated at a distance of 1.5-fold the height of the resolution before spurring movement. This research fencer, with respect to the big toe of the back foot. suggests the hypothesis that, in the situation of sim- After several simple attacks with a straight thrust at ple attack with target change, there will be an the pre-established distance, the plastron was moved increase in the two temporal components of the to a distance at which the fencer felt comfortable. reaction response time (RRT): a) simple reaction After the projection of the circle was set to the estab- time (RT) and b) movement time (MT) as conse- lished diameter, the distance chosen by each partici- quence of the reduction in horizontal velocity of the pant was maintained for all the trials in the two centre of mass (CM). experimental situations (straight thrust and target change). After the adjustment, the fencers reduced the distance to the plastron by 0.013 ± 0.2 m. The Methods fencers received instructions to remain still in the on-guard position until the circle was projected on Participants the plastron. From this instant, they were instructed A total of 30 fencers participated, each with experi- to make a simple attack with a straight thrust as ence in national competition for more than 10 years.